350 MW燃煤机组排烟余热利用系统热经济学分析

Thermoeconomic analysis of a flue gas waste heat utilization system for a 350 MW coal-fired unit

应用热经济学结构理论建立了某350 MW燃煤机组排烟余热利用系统模型,计算其火用成本、热经济学成本、分解的火用成本,分析机组的热经济性。结果表明:组件的产品单位火用成本不仅与其燃料单位火用成本有关,还与自身的火用效率有关;发电机(GEN)产品单位火用成本代表机组所产生电能的能量成本,经换算为0.18$/(k W·h);低温省煤器的不可逆现金成本和投资成本都较高,是导致其热经济学成本较高的根本原因;排烟余热利用后,各组件单位火用成本均有所下降,发电标准煤耗率降低了2.28 g/(k W·h)。

The model of flue gas waste heat utilization system for a 350 MW coal-fired power plant was carried out with the structure theory of thermoeconomic,calculating the exergy cost、thermoeconomic cost and disaggregated cost,to analyze the thermal economy of the power plant. The results show that the unit exergy cost of its product is not only related to the unit exergy cost of fuel,but also related to its exergy efficiency; the unit exergy cost of product of GEN is on behalf of the energy cost ofelectrical energy generated by the unit,The cost is about 0. 18 $/（ k W · h） after conversion; the basic reason causes the high thermoeconomic cost is that the high irreversible cash cost and investment cost of low temperature economizer; afterutilizing the flue gas waste heat,the unit exergy cost of each component decreases,standard coal consumption rate of power generation decreases 2. 28 g/（ k W·h）.